Wireless networks are designed to optimally provide system coverage of the geographic surrounding area. Different basestation antennas often have different azimuth beamwidths. The azimuth beamwidth represents the sector coverage of that particular basestation antenna. The network system designer chooses an antenna with a specific azimuth beamwidth based on predicted system usage in a given geographic area. Multiple fixed azimuth beamwidth antennas may be sourced for a network.
In an effort to reduce the number of antenna types required for a wireless network and ease the process of adapting a wireless network to changing demand levels, adjustable antennas can be used. With an adjustable azimuth beamwidth antenna a single antenna model can be purchased and each antenna that is installed in the network can be adjusted to the required azimuth beamwidth to optimize the network performance. Furthermore, due to changes in system demands over time the azimuth beamwidth can be adjusted in the field without removal or replacement of the antenna.
The antenna beamwidth can be controlled with metal plates, called baffles, that have a selected height and that are spaced a selected distance from the antenna radiating elements. Prior known adjustable azimuth beamwidth antennas have used large baffles attached to the antenna, increasing the antenna size and weight. Typically these baffles are external to the antenna. This type of antenna does not allow for easy field adjustability as multiple baffles, one on each side of the antenna, must be attached to the antenna. When external baffles are attached to an antenna, mechanical and environmental conditions such as wind, ice and snow load become an added concern.